1. Field of the Invention
The present invention relates to a foldable apparatus of a baggage cart, and more particularly to one which utilizes a new structure for enabling the foldable apparatus to fold and extend easily and perfectly.
2. Description of the Prior Art
Baggage construction used at the present time usually includes a baggage cart attached at a bottom thereof for ease of transportation. The baggage cart is equipped with wheels. These wheels occupy space when the baggage article is in storage. Moreover, the baggage article is apt to move due to these wheels when a user requires the baggage article to be positioned in place. Therefore, there are foldable baggage carts in which the wheels are allowed to retract. One of the conventional foldable baggage cart is illustrated in FIG. 10, which is attached at a bottom of an article of baggage 40 which is now shown in an empty status. The conventional baggage cart includes a base plate 41 made of metal or hard plastic, which has two elongate protrusions 42 formed near two sides thereof. Each elongate protrusion 42 defines a channel (not shown) therein for receiving a pivot 50. Each pivot 50 has two ends thereof extended outward from the channel and one end of the pivot 50 is integrally formed as a substantially U-shaped bracket 53 which has one branch 53' near the pivot 50 yet spaced from the pivot 50, while the other end of the pivot 50 is integrally formed as a post 52 to which a wheel 51 is rotatably connected. At two ends of the elongate protrusion 42 there is respectively formed an upright plate stop 43 which has a concave portion at substantially a center line thereof. When in operation, the branch 53' and the post 52 each has a portion respectively received in the concave portion of a corresponding upright plate stop 43. The branch 53' and the post 52 are retained in each corresponding upright plate stop 43 due to a self-deformation elastic force of the U-shaped bracket 53. When in storage, the pivot 50 is manually turned for substantially ninety degrees, therefore the bracket 53, the post 52, and the wheel 51 are in contact with the base plate 41 as shown in FIG. 10. However, this deformation elastic force in the U-shaped bracket 53 should be limited, otherwise the bracket 53 and the wheel 51 can not be retracted from the operation status to storage status easily. However, there are drawbacks in this foldable baggage cart. Firstly, the weight of the wheel 51 might cause the pivot 50 to turn in the channel defined in the elongate protrusion 42 when a user carries the baggage article while walking upstairs. Therefore, this foldable baggage cart might accidentally change from a storage status to an operation status thus causing inconvenience to the user. Secondly, the pivot 50 might turn in the channel defined in the elongate protrusion 42 due to a very heavy load in the baggage and especially when the baggage cart moves on a rugged surface. This is because the engagements between the upright plate stop 43 and the branch 53' of the bracket 53 and between the upright plate stop 43 and the post 52 are too weak to retain the baggage cart in operation status. Therefore, it is necessary to provide new structure for a baggage cart to mitigate and/or obviate the drawbacks of the conventional foldable baggage cart.